Flush valves for toilet tanks have one or more seats for a flap valve, i.e. flapper or ball and a stand pipe which protects the toilet tank from overflowing. Most commonly for two piece toilets; namely, toilets that have a separate tank that is attached to the bowl and rim member, the flush valve has a threaded bottom end which protrudes through a bottom tank opening and a threaded nut threadably engages the threaded section from the underside of the toilet tank to secure the flush valve in place.
One piece toilets with the toilet tank being integrally formed with the bowl and rim section or preassembled together before any of the tank apparatus is installed must have the flush valve mountable from the top of the tank.
Often this is accomplished by having a fixed threaded section or mounting ring mounted under the toilet tank outlet. The flush valve can have a rotatable threaded ring with internal ribs for engagement with a specialized tool for rotation therewith which when rotated tightens the stand pipe and valve seat against the bottom of the tank with a gasket interposed therebetween.
The problem with the previous mounting for one piece toilet tanks is that the valve seat has no height adjustment. Today's low water consumption toilets need a certain minimum amount of water for an adequate flush. A flush valve set too high would lessen the amount of water below the needed minimum. A flush valve set too low defeats the purpose of a low water consumption toilet and allows for waste of water. A height adjustment for the flush valve is necessary in low water consumption toilets. A second problem with present flush valves for one piece toilets is that a specialized tool is needed to rotate the inner ring for tightening the flush valve assembly onto the toilet tank.
What is needed with today's low consumption toilet in which a precise amount of water is needed to obtain an adequate flush is a flush valve adapter. The flush valve adapter can be threaded onto the threaded section below the toilet tank and has an upper end connected to a flush valve originally made for a two piece toilet tank which does not have the special rotating ring therein.
What is needed is a flush valve adapter that allows the height of the flush valve to be adjusted to provide for the precise amount of water needed for adequate flushes in low water consumption toilet tanks that can mount a flush valve with no needed special tools.